diff --git a/package/json-for-modern-cpp/json-for-modern-cpp.mk b/package/json-for-modern-cpp/json-for-modern-cpp.mk
index 4bcfd46910..e547c07875 100644
--- a/package/json-for-modern-cpp/json-for-modern-cpp.mk
+++ b/package/json-for-modern-cpp/json-for-modern-cpp.mk
@@ -5,7 +5,7 @@
 ################################################################################
 
 JSON_FOR_MODERN_CPP_VERSION = v3.1.2
-JSON_FOR_MODERN_CPP_SOURCE = json-${JSON_FOR_MODERN_CPP_VERSION}.tar.gz
+JSON_FOR_MODERN_CPP_SOURCE = json-$(JSON_FOR_MODERN_CPP_VERSION).tar.gz
 JSON_FOR_MODERN_CPP_SITE = $(call github,nlohmann,json,$(JSON_FOR_MODERN_CPP_VERSION))
 JSON_FOR_MODERN_CPP_LICENSE = MIT
 JSON_FOR_MODERN_CPP_LICENSE_FILES = LICENSE.MIT